1. Field of the Invention
The present invention relates generally to digital communication networks, and more specifically to a system and method for providing desired service policies to subscribers accessing the Internet.
2. Related Art
Users often access remote systems using local systems. In a typical scenario, a user may use a computer system (generally located close-by) to access a remote system (generally at a distant location). The access can serve as a basis for several useful applications such as web browsing, electronic mail and data base accesses as is well known in the relevant arts.
Remote access devices often exist between local systems and remote systems. A remote access device generally operates as an aggregator (concentrator) or multiplexor of physical connections (e.g., dialed connections over local loops and dedicated T1 lines from large groups) originating from users. The remote access devices generally operate to send digital data bits (“bit groups”) destined for the users, and receive bit groups originating from the users. Remote access servers (supporting digital and/or digital modems) provided by internet service providers (ISPs), digital subscriber line access multiplexors (DSLAMs) provided by local exchange carriers (conventional and competitive LECs), and cable modems provided by cable television providers are examples of such remote access devices.
A remote access device commonly interfaces with a data switch, which selectively forwards each received bit group to a corresponding destination, typically based on address information encoded in the bit groups. In a common implementation, a data switch corresponds to an Internet Protocol (IP) router, which examines the destination address of an IP packet to determine the next point (typically another router or computer system) to send the IP packet to.
In a conventional implementation, combination of routers and remote access devices may not serve particularized requirements (or desired service policies) of users. A group of users (including the case of a single user) having specific service policy requirements will be referred to as a subscriber in the present application. Examples of particularized requirements of subscribers are first noted. Then, the inadequacy of conventional routers and remote access devices in meeting user requirements is described.
Subscribers may have particularized requirements for several reasons. For example, a subscriber containing a large group such as a business, and the business may wish to limit the aggregate bandwidth used by some or all of the users. Some other business may wish a virtual private network (VPN), having dedicated secure links between different distance locations perhaps for some users but not all. Yet another business may wish to restrict inbound access to certain types of applications (e.g., only web accesses, but not file transfers or telenet) or have different classes of service (COS's) for different applications.
On top of such requirements for large groups, individual users (subscribers) may have different requirements. These individuals may be part of a large business or home users. A user may wish to be allocated only 56 Kbps during some peak times (e.g., business hours when networks are typically more congested), and much higher bandwidth during other times. An ISP may wish to charge lower rates for such users. In general, it should be appreciated that the users or subscribers can have varying and particularized service policy requirements.
Conventional combinations of data switches and remote access devices may be inadequate in serving a combination of such requirements for several reasons. For example, data switches may be implemented primarily as fast packet forwarding devices, albeit with limited prioritization and access control schemes. Asynchronous transfer mode (ATM) switches prioritizing traffic based on quality of service (QoS) and traffic parameters, and IP routers filtering data of only some applications are illustrative examples.
However, the architectures chosen for conventional data switches and/or remote access devices may not provide for customization of service policies for individual users/subscribers. For example, ATM switches forwarding cells may not have the ability to distinguish between individual users by the examination of a single cell. Data switches operating at higher layers (e.g., IP routers) may be designed to process packets uniformly, usually for attaining speed, and thus may not be designed to provide customized service policies to individual subscribers.
As noted above, such customization may be required in several instances. Therefore, what is needed is a flexible architecture which enables the provision of different customized service policies to different subscribers.
In addition to customization, it is generally necessary that the architecture scale to serve a large number of subscribers. Therefore, what is also needed is a flexible architecture which scales well to serve a large number of subscribers.